The specific aim of this proposal is the establishment of a rapid, non-deleterious, quantitative measure of single rabbit and human cornea viability for the purpose of easing the chronic shortage of good tissue available for transplantation. The proposed method is based on the quantitation of phosphorous-containing metabolites in the endothelium of the cornea, in particular ATP, by very high field (11.5 T, 202.5 MHz) phosphorous-31 nuclear magnetic resonance (NMR) spectroscopy. Interest in the endothelium arises because this delicate non-regenerating tissue component of the cornea is primarily responsible for the control of corneal hydration by means of an ATPase-dependent pump, and in turn maintenance of corneal clarity, the chief difficulty in graft failure. If adequate quantitation of phosphorous-containing metabolites can be achieved by NMR spectroscopy, the next step, which is beyond the scope of this proposal, will be to correlate the success of animal keratoplasty studies with specific endothelial metabolite levels.